In this case, his base also lobbied hard for the move. That included right-wing American Jews whose message was amplified by the conservative orthodox Jews dominating Mr Trump's inner circle.

Media captionWhy the ancient city of Jerusalem is so important

It also included evangelicals whose voice was amplified by the devout Christian in the White House, Vice-President Mike Pence.

"God decided Jerusalem was the capital of Israel more than 3,000 years ago during the time of King David," I was told by Dallas evangelical pastor Robert Jeffress, who cited Biblical history. He and another leading voice in the pro-Israel part of the Christian world delivered prayers at the opening ceremony.

"The United States remains fully committed to facilitating a lasting peace agreement," Mr Trump also said in his recorded message.

He has declared an interest in solving the "toughest deal of all" and, despite the outrage over Jerusalem, the White House is still intent on rolling out a detailed initiative of a settlement it thinks is achievable.

And the Palestinian deaths in Gaza make that prospect even less likely.

The administration argues it is simply recognising the obvious in accepting Jerusalem as Israel's capital and that the city's final boundaries can still be determined in negotiations.

But confusingly, Mr Trump has also said he has taken the issue "off the table". And he has failed to say anything about Palestinian claims to East Jerusalem.

So whatever the intent, he appears to have sided with Israel on one of the most volatile issues in the peace process and prejudiced the final outcome of any talks.

Does this mean an explosion?

The Trump administration has also sided with Israel in its response to the deadly violence on the Gaza border.

The White House accused Gaza's Hamas leaders of "intentionally and cynically" provoking Israel in an attempt at "gruesome propaganda" but, unlike European countries, it did not call on the army to exercise restraint.

Hamas has been directing the weeks-long protest campaign by Palestinians frustrated with Israel's economic blockade of Gaza.

Analysts said it was a chance for the militant Islamist movement to shift the blame for its own poor performance in government.

The question now is whether the hundreds of casualties will trigger an uprising, or intifada, that spreads to the West Bank.

The Jerusalem decision itself did not do so and there are many reasons why the Gaza violence may not. That includes divisions in the Palestinian leadership and the high cost for Palestinians of a return to sustained conflict.

But it is a volatile situation fuelled by a sense of Palestinian hopelessness that could lead to further escalation.

Crossing a red line?

What seems more likely to me at the moment is a slower unravelling of the peace process framework which for the past 25 years has led to neither peace nor all-out war.

Despite spasms of conflict, it has maintained certain fundamentals.

The Israelis have not annexed the West Bank. The Palestinian Authority continues security co-operation, in effect helping Israel police its own people.

The framework is held up by an American mediator that is seen by many as somewhat credible, if not neutral.